1. Field of the Invention
Embodiments of the present invention relate generally to an improved data processing system, and in particular to a computer implemented method, data processing system, and computer program product for using a filter range based search control in a communication protocol to request a range of sorted data from one or more directory servers.
2. Description of the Related Art
A directory is a special type of database for managing information about people, organizations, data processing systems, and other information sources. Information within a directory is organized within a hierarchical namespace. Each entry in the directory is a named object and consists of a set of attributes. Each attribute has a defined attribute type and one or more values. Each entry is identified by an unambiguous distinguished name (DN), wherein a distinguished name is a concatenation of selected attributes from an entry. A directory service provides a mechanism for searching a directory and for retrieving information from a directory.
Directory services serve as central repository for searching, adding, deleting and modifying data. Example methods of accessing directory services in a computer network include X.500 and Lightweight Directory Access Protocol (LDAP), among others. Lightweight Directory Access Protocol (LDAP) is a software protocol for enabling a user to locate organizations, individuals, and other resources such as files and devices in a network, whether on the Internet or on a corporate Intranet. LDAP is a “lightweight” version of Directory Access Protocol (DAP), which is part of X.500, a standard for directory services in a network.
In certain situations, it may be desirable to limit the number of search items that are returned to the client from the directory server. One such instance is when the requesting client has limited resources or is connected to a directory server via a low-bandwidth connection. In existing systems, one common method of limiting the number of search items returned to the client is through the use of a paged search results function. A paged search results function may be used in a communication protocol to control the rate at which data is returned to the client from the directory server, such that the client may receive a few entries (a page) at a time rather than receiving all of the search results at once. The paged search results function is defined by Request for Comments (RFC) 2696 published by the Internet Engineering Task Force (IETF).